First confession: am currently a Pentax DLSR user of many years. However I am very seriously considering a complete switch to the Olympus MFT system, particularly after being captivated by the cameras at the recent NEC Photography Show. So, am here for advice and encouragement.

Weight is certainly a factor in my choice, both for camera and lens. I was amazed at how small the OMD cameras were on the Olympus stand plus they offer features not available with my current kit. I think it is just a question of timing. I may wait until the summer is over before changing- hopefully a price drop will come around for the OM-D E-M1 11! One can but hope!

I have owned Pentax for 50+ years (still have a K3), they and their glass are fantastic . But comes a time when innovation (and weight) starts to make one wonder. 18 months ago we planned a 4 month world trip - this was crunch time.
Looked at all the MFT Brands, and respected Olympus for what they delivered back in the film days.

I am very happy I made the change.

However Oly Menus are a pain in the butt - best to concentrate on what you want from the system, rather than chase what it can offer, (insanity lies with trying to understand all the bells & whistles, many of which, to me, seem nerdish).

Glass is very good at most levels and good second-hand deals can be had. Depends on your shooting style what you go for.

Guess my only point is your choice of the M1 Mkii. Obviously the bees knees, but again, depending on your shooting style, it's a bigger beast - have a look at the M5 Mkii.

I made the switch from Pentax to Olympus a few months ago. I really enjoyed using the Pentax system, and found the bodies (from K-m through to K-3 series) had fantastic handling. A very underrated camera by many. But for me their biggest failing was autofocus. Whilst perfectly adequate it wasn't up to the same standard as many of its competitors. I was also looking to get a smaller and lighter system to carry around all day.

The autofocus on the E-M1 ii I've now got is streets ahead of the Pentax. Now I get many more in focus shots with moving subjects. There's also a good selection of much smaller and lighter lenses. Much easier to carry around all day.

The trade off for me is a bit more noise in many images, and a menu system that takes a lot of learning (still learning it) - but overall the advantages for me make it a good choice. I don't regret the system change so far.

Thank you for all of the helpful and encouraging replies. Yes, Pentax make severely underated cameras, solidly built and very good performers. However, I do find their kit and lenses heavier to carry as I get older plus the autofocus does lead to lost shots as many have said.Yes, the E M1 11 is larger than some of the other Olympus offerings but it has the features I want and I intend not to use a grip as I do on my Pentax K3. And yes I do realise the need to stock up with extra batteries! Hopefully the sale of my Pentax kit will contribute nicely to the purchase of the M1 11.